// The part of an OCR result this module reads, as a schema: what is kept as the OCR stage's cached
// artefact, so a file read once is not paid for twice. Words and polygons are not kept, and the
// SDK's own `OcrDocument` is assignable to the type this yields.

import { z } from "zod"
import { PAGE_CLASSES } from "../contract/index.js"
import type { ReadDocument } from "./ports.js"

const lineSchema = z.object({
  text: z.string(),
  bbox: z.tuple([z.number(), z.number(), z.number(), z.number()]),
  confidence: z.number(),
  order: z.number(),
  repeated: z.boolean(),
})

const blockSchema = z.object({
  id: z.string().min(1),
  bbox: z.tuple([z.number(), z.number(), z.number(), z.number()]),
  order: z.number(),
  lines: z.array(z.number().int().min(0)),
})

const pageSchema = z.object({
  index: z.number().int().min(0),
  width: z.number(),
  height: z.number(),
  class: z.enum(PAGE_CLASSES),
  source: z.enum(["ocr", "text_layer", "spreadsheet"]).optional(),
  text: z.string(),
  lines: z.array(lineSchema),
  blocks: z.array(blockSchema),
})

export const readDocumentSchema: z.ZodType<ReadDocument> = z.object({
  engine: z.object({ name: z.string(), version: z.string() }),
  page_count: z.number().int().min(0),
  pages: z.array(pageSchema),
})

/** What of a document is worth keeping: exactly the fields of `ReadDocument`, and no more. */
export const projectDocument = (document: ReadDocument): ReadDocument => readDocumentSchema.parse(document)